1. Field of the Invention
This invention relates to a lens, more particularly to a lens for correcting vision of a user.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional lens 1 for correcting vision of a user includes a central zone 11, and an outer zone 12 surrounding the central zone 11. The central zone 11 and the outer zone 12 have different curvatures. Ina case of the user being myopic, the central zone 11 causes light passing therethrough to forma clear image on a retina 19 of an eye of the user, and the outer zone 12 causes light passing therethrough to form an image in front of the retina 19 at a point (Q), i.e., a blur or defocus image, which is slightly myopic to the user. It has been proven in many researches and studies that such design may slow down myopia aggravation of the user.
However, the outer zone 12 of the conventional lens 1 having a single curvature can only provide a defocus image in front of the retina 19 at a fixed position, which may not be suitable for various eyeball configurations of different users.